log: make the name of error clearer
log: make the name of error clearer

Change-Id: Id0398b51336cc74f2172d9b8e18cb1dcb520b9a0
GitHub-Last-Rev: b5cf80bf9d7f79eab1a398ad3c03f3b424aafdf1
GitHub-Pull-Request: golang/go#29931
Reviewed-on: https://go-review.googlesource.com/c/go/+/159537
Reviewed-by: Emmanuel Odeke <277f8eaa8c7dfbc55c17bf5e30561c1a9c45c569@gmail.com>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
Run-TryBot: Emmanuel Odeke <277f8eaa8c7dfbc55c17bf5e30561c1a9c45c569@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

golang/go,golang/go,cloudflare/go,josharian/go,josharian/go,nawawi/go,nawawi/go,josharian/go,nawawi/go,nawawi/go,akutz/go,akutz/go,akutz/go,CAFxX/go,akutz/go,akutz/go,cloudflare/go,golang/go,CAFxX/go,akutz/go,josharian/go,golang/go,akutz/go,golang/go,akutz/go,nawawi/go,josharian/go,josharian/go,cloudflare/go,CAFxX/go,CAFxX/go,nawawi/go,josharian/go,CAFxX/go,golang/go,golang/go,CAFxX/go,josharian/go,CAFxX/go,CAFxX/go,cloudflare/go,nawawi/go,cloudflare/go,cloudflare/go,golang/go,nawawi/go,cloudflare/go,cloudflare/go